There appears to be nothing nefarious in the move, other than no official announcement, as the rise in cost is because an increase in the price of NAND flash memory used in the iPad Pros, knowledgeable sources told 9to5 Mac. The following units are affected:

10.5-inch 256GB: $799

10.5-inch 512GB: $999

12.9-inch 256GB: $949

12.9-inch 512GB: $1149

Apple did not raise the prices of the 64GB models, as the 10.5-inch stayed at $649, and the 12.9-inch maintained its $799 cost.

Apple CFO Luca Maestri had warned of increased NAND prices in Apple's second quarter earnings call earlier this year, telling analysts that "We started to experience some level of cost pressure on the memory side, particularly on NAND and DRAM. To offset that and actually do better than that, we had very good cost performance on other commodities. The impact on NAND and DRAM will continue to be there and we expect it to be there."

The new iPhone 8 could also be causing the NAND price increase as well, given that the new unit also uses the flash memory. Reports back in June suggested that orders for both NAND and DRAM by Apple were causing worldwide shortages, and other phone manufacturers were ordering the components long before they needed to so they could maintain supply.